Safety switch structure



NOV. 19, 1929. J, F, MacWlLLlAMS 1,736,452

SAFETY SWITCH STRUCTURE Filed March 21, 1928 gyz,

Inventor j? Jifiril i'llmmg Amrngy Patented Nov. 19, 1929 v UNITEDSTATES JAMES F. MACWILLIAMS, OF CRESSON, PENNSYLVANIA SAFETY SWITCHSTRUCTURE Application filed March 21, 1928. Serial No. 263,457.

The present invention pertains to improvements in switch structures andhas for its principal object the promotion of the factor safetythroughout its operable details.

' An important object is to provide switch structure for controllingelectrical circuit, which includes a housing having an open side and acover for said open side which can only be removed after the switchcontacts have been disengaged.

Another object is to provide switch structure of the above characterwhich includes means for maintaining the switch contact disengaged whenthe operating means employed have been detached therefrom.

Still another object resides in the provision of novel lock means formaintaining the switch element in contacting position, and at the sametime locking the cover to the housing securely and against possibilityof removal, excepting when the switch element 1s moved to open position.

Other novel and advantages will become apparent as the invention isbetter understood 1 26 from the following specification and claims.

In the drawings Figure 1 represents a cross sectional view through theswitch structure, and disclosing the details thereof in sectional view.

Fig. 2 is a sectional View on the plane with the open side of thehousing, disclosing the position of the contact carrier shown indisengaged position, and

Fi 3 represents a perspective view of the T slida le contact carrier.

the housing, while a hollow projection 1 is provided at the opposite endof the housing, and in substantial alinement with the boss 3.

A block 5 of insulating material, is arranged within the housing in themanner clearly shown in Fig. 1. This block is formed with a pair ofspaced openings adapted to receive a fuse member or cartridge 6.

The conductor wires 7 may be led through the tubular nipple 2 atone.'side of the housmg. The cover which is generally referred to bynumeral 8, comprises a plate 9 provided with a depending rectangularflange 10 which is adapted to fit snugly within the open side of thehousing 1. The cover is provided with a laterally projecting flange 11which engages over the open edge of the housing for protective purposes.The top side of the cover 1s provided with an upstanding nipple 12 thruwhich the conductors 13 are led.

As is clearly shown in Fig. 1, a block of insulating material 14: issecured within the flanged area of the cover, and formed throughout itslength with a bore 15. A pair of spaced contact members 16 are securedwithin the block 1 1, so that theirouter ends are normally in contactwith the respective ends of the fuses 6. A pair of contact members 17-17are embedded in the block Hand spaced from the respective contacts 16 bythe bore 15.

A slide 18 is provided with a pair of contacts 19-19 which extendtransversely through the slides and terminate in flush relation withopposite sides of the same.

This slide is adapted for reciprocatory movement within the bore 15 in amanner so as to cause the contacts 1919; 17-17 and the contact 1616, foreffecting a closed circuit.

The flange 10 of the cover is formed with an opening registrable withthe open inner end of the hollow projecting 4 and a second opening atthe opposite side of the cover registrable with the bore of the boss 3.

The slide 18 is provided at one end with a longitudinally projectingguide rod 20, which is adapted to have its outer end portion proj ectedthrough the opening in the cover flange and for inserted dispositionwithin the hollow projection 4., when the slide 18 is moved tocontacting relation with the contact 17 respectively.

A coiled spring 21 convoluted about the guide rod 20, is adapted to haveone end thereof bear against the flange of the cover, while its oppositeend bears against the adjacent end of the slide 18, for tensionallymaintains ing the opposite end of the slide in contact with the oppositeportion of the flange and in open circuit position.

For the purpose of shifting the slide to closed position, a key 22 isinsertible through the bore of the boss 3 so that its end portions willengage in a socket or suitable recess in the adjacent end of the slide.The boss 3 is formed with a bayonet slot 23, or in fact any similarformation, that may receive a pin 24 on the key, when the key has beenforced inwardly and turned in the proper direction.

Obviously, when the key is moved i11- wardly, the slide 18 will beshifted in the bore 15, against the tension of the spring 21, by whichmovement, the guide rod 20 will engage in the hollow projection 4through an openinginthe flange, 10. By turning the key slightly in theproper direction, the pin 24: will engage in the ofiset slot of thebayonet slot. 23, whereby the slide will be maintained in. closed.position with its contact in engagement with the contacts 16 and 17respectively.

When, it is desired to remove the cover, the key 22 is removed so thatthe slide 18 will be urged to the position shown in Fig. 1, by thetension of the spring 21. In this position, with the key 22 removed, thecover may be lifted fromv its connection with the housing. Thus it willbe seen that the circuit is broken and complete access available to allparts of the structure.

Having thus described my invention, what I claim as new is 1. In aswitch structure comprising, a housing open at one side,a cover for saidhousing, said cover being provided with a rectangular shaped flange atits inner side, said flange being adapted to snugly fit within thehousing, a slidable contact member carried by said cover at its innerside, a member at one end of theslidable contact for interlocking thecover'flange with. the housing, tensional means for-normallymaintaininthe contact member in, opening position, an means for moving and lockingthe slidable contact in closed position; i

2., A, switch structure comprising a housing, said, housing being openat one side, a cover for the open side of the housing, a switch membermovable within said housing, a bolt carried by the switch member forsecuring the cover to the housing, and a key for securing the cover tothe housing, said key being operable to move the said switch member toclosed positiom.

3 A switch structure comprising a housing, said housing being open atone side, a cover for the open side of the housing, a switch membermovable within said housing, a bolt carried by the switch member forsecuring the cover to the housing, a key for securing the cover to thehousing, said key being operable to move the said switch member toclosed position, and complementary means between the key and the housingfor retaining the switch member in closed position.

4. A switch structure comprising a housing, said housing being open atone side, a cover for the open side of the housing, a switch membermovable within said housing, a bolt carried by the switch member forsecuring the cover to the housing, a key for securing the cover tothehousing, said key being operable to move the said switch member toclosed position, and complementary means between the key and the housingfor retaining the switch member in closed position, and spring means formoving the switch member to open position when the complementary meansis released.

In testimony whereof I aifix my signature.

JAMES F. MACWILLIAMS.

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